Apparatus for conducting controlled well testing operations

ABSTRACT

A well testing apparatus, and method for effecting well testing, wherein a translatable barrier means is operable to both permit and indicate a flow of formation fluid through a testing string portion while continuously preventing a transmittal of fluid from a formation being tested to a well head and/or a flow of such fluid past the barrier means. In practicing this method and utilizing this apparatus, an abruptly operable indicating means is operable in response to a generation of pressure within a testing string to provide a well head indication that such a pressure generation has been achieved.

United States Patent 1 Jessup Oct. 2, 1973 [5 APPARATUS FOR CONDUCTING CONTROLLED WELL TESTING OPERATIONS Primary ExaminerJerry W. Myracle Attorney-James E. Cockfleld [57] ABSTRACT A well testing apparatus, and method for effecting well testing, wherein a translatable barrier means is operable to both permit and indicate a flow of formation fluid through a testing string portion while continuously preventing a transmittal of fluid from a formation being tested to a well head and/or a flow of such fluid past the barrier means.

In practicing this method and utilizing this apparatus, an abruptly operable indicating means is operable in response to a generation of pressure within a testing string to provide a well head indication that such a pressure generation has been achieved.

7 Claims, 22 Drawing Figures PAIENTEDIET 2 m SHEET 2 0F 5 HGZcI FIGZ PATENTED BET 2 73 SHEET 3 BF 5 6 w m 00 K I fww BIO

PATENTED 2 75 SHEET 5 [IF 5 APPARATUS FOR CONDUCTING CONTROLLED WELL TESTING OPERATIONS GENERAL BACKGROUND, OBJECTS AND SUMMARY OF INVENTION In connection with the evaluation of well formations, a variety of devices and techniques have been proposed for evaluating the pressure of well formations and obtaining a sample of fluid from formations being tested.

In certain instances it is desirable that such testing operations be performed without transmitting formation fluid to the wellhead during the testing operation itself.

Such a prevention of transmission of formation fluid is desirable where it is imperative or important to maintain secrecy in relation to the results of the formation test.

In other instances it may be desirable to prevent the transmission of formation fluid to a wellhead because of the potentially harmful or noxious nature of the formation fluid itself. Thus, for example, formation fluid having a hydrosulphide gas content is potentially dangerous and it would be desirable to insure that such formation fluid would not be transmitted to the wellhead during a testing operation so as to insure the safety of personnel in the vicinity of the wellhead.

Certain techniques have heretofore been proposed for achieving secrecy and/or safety controls of this general nature.

For example, United States Nutter Patent No. 3,422,896, United States Jensen Patent No. 3,412,607 and United States Raugust Patent No. 3,356,137 each relate to techniques for effecting formation testing under certain conditions of control.

However, in each instance, these three prior art patentees contemplate arrangements which would permit a flow of fluid from a formation to a wellhead or past a barrier means during a sample recovery operation.

In the event that such a valve mechanism should be improperly operated, the secrecy of a testing operation would be vitiated. In the event that dangerous or noxious formation fluids were being handled, a failure to properly operate the valve mechanism could easily produce a potentially hazardous wellhead situation.

During testing operations it may become desirable to provide an indication at a wellhead that a particular pressure level has been generated within a testing string.

A prior art approach at providing such an indication is described in the aforesaid Nutler US. Pat. No. 3,422,896. However, the Nutter indicating mechanism inherently operates as a dash-pot apparatus to provide impeded movement of components of a pressure generation indicating mechanism.

Rather than being vulnerable to the inertia of a dashpot type mechanism, it would be preferable to provide an abrupt and timely indication of the generation of a particular pressure level in a testing string so that an operator at the wellhead would be promptly informed of testing conditions.

Bearing these general criteria in mind, and recognizing the state of the art as heretofore developed, it is a general object of the invention to provide a method and apparatus for effecting formation testing such that a flow of formation fluid into a testing apparatus is permitted, while positively and continuously preventing a transmission of such fluid to a wellhead and/or past a barrier means.

It is likewise an object of the invention, in an independent sense, to provide an abruptly operable and novel mechanism for indicating at the wellhead that a particular pressure level has been achieved within a testing apparatus.

It is also an object of the invention to provide an improved valve system for effecting the controlled removal of formation from the interior of a testing string.

In accomplishing at least certain of the foregoing objectives, a method of performing well operations is presented through this invention which initially entails the disposing of well formation testing means in a well bore. A barrier means is translated within this conduit means while permitting a flow of formation fluid through the well formation testing means but continuously blocking a transmittal of fluid from the well formation testing means to the wellhead means and/or past the barrier means. A signal or indicating means, carried by the conduit means, is abruptly operable to indicate a generation of pressure within the conduit means in response to a flow of well fluid through the well formation testing means. Thereafter a circulating valve means is operated to remove fluid from the conduit means beneath the translatable barrier means.

An independently significant method aspect of the invention entails a method of testing well formations where well formation testing means is disposed in a well bore. Again, a conduit means is provided which is operable to extend in the well bore from the well formation testing means to wellhead means.

Included in this conduit means is a first stop means carried by the conduit means and a second stop means carried by the conduit means. A barrier means is carried by the conduit means and interposed between the first and second stop means.

The barrier means is translated between the first and second stop means in response to a flow of fluid from the well formation testing means through the conduit means while continuously preventing a passage of fluid from the well formation testing means to the wellhead means and/or past the barrier means. In response to this translation of the barrier means, an indication is provided at the wellhead of a flow of well fluid into the well formation testing means.

Other independently significant aspects of the invention relate to various combinations of apparatus means operable to accomplish either or both of the foregoing method aspects of the invention.

Another independently significant apparatus facet of the invention pertains to structure of the aforesaid signal means.

This signal means comprises generally telescopingly assembled first and second portions of the conduit means which extends between the wellhead means and the well formation testing means. A detent means is included in the signal means and is operable to secure the first and second portions of the conduit means in a first predetermined position. A pressure responsive means, included in the signal means, is operable to move in response to exposure to fluid pressure external of the conduit means in the well bore to release this detent means and permit relative movement of the first and second portions of the conduit means to a second position. A differential pressure operated means included in the signal means and carried within the conduit means is operable in response to a generation of pressure within the conduit means to cause the pressure responsive means to be exposed to the pressure of fluid external of the conduit means.

A unique hydraulic system for counteracting forces tending to impede operation of the aforesaid detent means is also of independent significance.

Another independently significant apparatus facet of the invention relates to structure of the aforesaid circulating valve means.

This structure includes first circulating valve means carried by the conduit means and comprising sleeve valve means and turnbuckle means. The sleeve valve means is carried by the conduit means and operable to control fluid communication between the interior and exteriorof the conduit means. The turnbuckle means, which is manually operable at the wellhead means, is operable to effect valving operations of the sleeve valve means. I

A second circulating valve means included in the circulating valve means is carried by the conduit means and includes rupturable means and pressure relief valve means. The rupturable means is operable when ruptured to provide fluid communication between the interior and exterior of the conduit means. The pressure relief valve means is operable to limit the generation of static pressure within the interior of the conduit means adjacent the rupturable means. The first and second circulating valve means are spaced longitudinally of the conduit means.

Particular advantages are derived from overall combinations of the various apparatus aspects noted above.

DRAWINGS In describing the invention reference will be made to preferred embodiments shown in the appended drawings.

In the drawings:

FIGS. 1a through If provide a schematic series of views illustrating certain sequential manipulations involved in a well testing operation during the practice of the present invention;

FIG. 1a illustrates a testing string disposed within a well bore at commencement of a testing operation;

FIG. lb illustrates the FIG. 1 apparatus near the conclusion of a testing phase involving a flow of formation fluid;

FIG. 1c illustrates the FIG. 1a apparatus after telescoping components have been abruptly converged to provide a wellhead indication of the generation of a testing pressure within the interior of the testing string;

FIG. 1d illustrates the FIG. la apparatus after the apparatus has been raised at the end of a testing operation so as to dispose manually operable circulating valve at a location at the wellhead accessible to operating personnel;

FIG. 1e illustrates the testing string, as disposed in FIG. 1d, and schematically indicates the manner in which fluid is pumped at the wellhead into the interior of the conduit string so as to effect the opening of another circulating valve, carried by the testing string but disposed within the well bore;

FIG. 1f schematically indicates a circulating technique which may be employed to effect the removal of formation fluid from the interior of the testing string;

FIG. 2 provides an enlarged, longitudinally sectioned fragmentary view of a portion of the FIG. la testing string, illustrating details of a translatable barrier means and a manually operable valve means during an intermediate phase of a formation flow;

FIG. 20 provides a view of the FIG. 2 components at the conclusion of a flow phase of a testing operation;

FIG. 3 provides a still further enlarged view of a portion of FIG. 2, illustrating a turnbuckle operated, sleeve-type circulating valve mechanism which is operable at a wellhead as described in connection with FIG. 141;

FIG. 4 provides a transverse sectional view of a spline mechanism associated with the turnbuckle mechanism of FIG. 3, as viewed along section line 4-4 of FIG. 3;

FIGS. 5, 6 and 7 joined respectively along juncture lines aa, b--b, c--c, provide an enlarged, longitudi nally sectioned, fragmentary view of a portion of the FIG. 1a apparatus illustrating components of a pressure generating indicating or signal means, with these components being disposed in their normal or relaxed condition;

FIG. 8 provides a transverse, sectional view of a detent mechanism which serves to control the telescoping movement of conduit components of the FIG. 5-7 indicating mechanism, as viewed generally along section line 88 of FIG. 6;

FIGS. 5a through 7:: provide illustrations of the components of the FIG. 5-7 mechanism, with these components being disposed as they would be located in response to the generation of a pressure within the interior of the conduit string sufficient to permit the FIG. 8 detent means to permit relative telescoping movement of telescope conduit portions of the testing string;

FIG. 8a illustrates the FIG. 8 detent means in the position operable to permit the aforesaid telescoping movement;

FIG. 9 provides an enlarged, longitudinally sectioned, fragmentary view of the FIG. 1a assembly illustrating components of a rupturable circulating valve mechanism associated with pressure relief means;

FIG. 10 provides a still further enlarged view of that portion of FIG. 9 which encompasses the aforesaid pressure relief means;

FIG. 10:: provides a view of the components of the FIG. 10 relief valve mechanism, with these components being shown in exploded format; and

FIG. 11 provides an enlarged view of that portion of FIG. 9 which is directed to a rupturable circulating valve mechanism.

OVERALL DESCRIPTION OF APPARATUS FIGS. la through 1 f schematically illustrate the manner in which a testing string, assembled in accordance with the present invention, is positioned and manipulated to effect the evaluation of a subterranean formation means.

As shown schematically in FIG. In, this testing string 1 may comprise, in downwardly extending sequence, the following components:

Components Reference Numeral Testing string conduit sections (usual y threadably interconnected) 2 Upper stop means 3 Upper circulating valve means (manually operable) 4 Conduit section which may comprise desired assembly of drill pipes and drill collars 5 translatable barrier means 6 Lower stop means 7 Pressure generation indicating means 8 Lower circulating valve means 9 Hydraulic impedance mechanism 10 Tester valve 11 Extension joint 12 Pressure recorder 13 Jar mechanism 14 Safety joint 15 Tester packer 16 Perforate anchor pipe 17 Blanked-ofi' pressure recorder 18 Asshown schematically in FIG. 1a, tester string 1, which may be assembled with components as heretofore described, is disposed in a well bore 19.

Testing string 1 is located in well bore 19 such that a perforate anchor pipe 17 is disposed in fluid communicating relation with a subterranean formation 20, the pressure and fluid characteristics of which are to be evaluated.

Packer 16 serves to isolate formation 20 from the portion of well bore 19 above the formation 20 by engaging the periphery of well bore 19 (which may or may not be cased).

Testing string 1 extends upwardly through well bore 19 to wellhead 21, generally indicated in FIG. la, and may be supported at its upper end by conventional hoisting and manipulating means 22.

Novel aspects of the invention, which will be discussed in detail, relate to structural and manipulative characteristics of the upper and lower stop means, 3 and 7 respectively, which cooperate with the translatable barrier means 6. Other novel aspects of the invention, which will be discussed in detail, pertain to the indicator or signal means 8 and the composite circulating valve means 4 and 9.

The remaining individual components of testing string 1 may be selected from components heretofore available. I

For example, the impedance mechanism 10, which serves to effect controlled lineal movement of components of testing string 1 during the testing operation, may comprise an apparatus of the type described in U.S. Schwegman Pat. No. 2,740,479.

The tester valve 11 may comprise a multiple completion, closed in sampler valve of the type generally described in U.S. Chisholm Pat. No. 3,358,755 and featured on page 144 of the 1968 I-Ialliburton Sales & Service Catalogue available from I-Ialliburton Services, Duncan, Oklahoma.

Extension joint 12 may comprise a telescoping joint corresponding in general to the extensible joint 8 featured in the aforesaid Chisholm Pat. No. 3,358,755 and/or the extension joint 15 featured in a pending U.S. Manes et al. application Ser. No. 882,856, now U.S. Pat. No. 3,646,995 assigned to the assignee of the present invention, and the disclosure of which is herein incorporated by reference.

Recorders 13 and 18, which serve to record the pressure of formation fluid within the interior of the testing string, may comprise a variety of formation testing recording devices, including those described in the aforesaid 1968 Halliburton Sales & Service catalogue in connection with well testing apparatus.

Jar mechanism 14 preferably comprises a hydraulic jar mechanism of the type featured for example in U.S. Barrington Patent No. 3,399,740 and/or U.S. Barrington Patent No. 3,429,389.

Safety joint 15 may comprise a mechanism for permitting selective separation of the packer bearing, lower portion of the testing string from the upper testing string portion. The safety joint 15 may comprise, for example, a safety joint of the type in U.S. Barrington Patent No. 3,368,829.

Packer mechanism 16 may comprise a packer mechanism of the type used for well testing purposes to isolate a test zone from a well annulus 19a above the test zone. Such a packer mechanism may comprise a locked down tester packer available from Halliburton Service, Duncan, Oklahoma and may also comprise other testing packer arrangements, including an RTTS tester packer described for example on page 62 of the aforesaid 1968 l-Ialliburton Sale & Service Catalogue.

As will be understood, the testing string heretofore described comprises an assembly of usually threadably interconnected and generally cylindrical body components. The interior of these body components provides a longitudinally extending passage which permits formation fluid to flow into the perforate anchor pipe 17 and thence through the testing string. However, as will be hereinafter described, this formation fluid is prevented from passing through testing string 1 to wellhead 21 by the translatable seal or barrier means 6.

The manner in which components 10 through 18 function is not known and may be readily comprehended by those skilled in the testing art. Reference to patents and publications heretofore noted will provide specific descriptions of the mode of operation and manipulation of these components.

Thus, the present discussion will be confined to novel aspects of components 3 through 9.

Prior to describing the manner in which these components perform to improve the control and safety aspects of well testing operations, reference will be made to detailed structural aspects of these components.

BARRIER MEANS STRUCTURE Testing string 1 includes a barrier means structure comprising first stop means 3, second stop means 7, and the translatable barrier 6.

As shown generally in FIG. 2, first or upper stop means 3 may comprise an annular shoulder 301 which extends, radially or transversely across a central longitudinal passage 101 of testing string 1. As shown in FIG. 2, annular shoulder 301 faces generally downwardly.

The second or lower stop means 7 similarly comprises a radially or transversely oriented shoulder 701 which extends across central tool passage 101.

Barrier 6 is disposed in passage 101 between the downwardly and upwardly facing top surfaces 301 and- 701.

Barrier 6 may comprise a multiple stage, cementing shut-off plug of the type generally described in the 1968 Halliburton Sale & Service Catalogue. An exemplary plug is featured, for example, in FIG. 3 of page 9 of this catalogue.

Referring again to FIG. 2, it will be noted that the plug 6 is disposed in passage 101 so as to be movable in an upward direction in response to the pressure of fluid acting there beneath.

At the commencement of a testing operation, and when the string 1 is initially positioned in the well bore 19, plug 6 will be disposed in supported or abutted engagement with shoulder or stop 701. A flow of fluid upwardly through passage 101, beneath stop means 7, will engage plug or barrier 6, and cause upward movement of this barrier or plug toward the upper stop 301.

Upper movement of plug or barrier 6 will continue until the plug engages shoulder 301 at which point upward movement of the plug is arrested.

Upward movement of plug or barrier 6, as heretofore described, will upwardly displace fluid which may be present in passage 101 above the plug or barrier 6. This displacement of fluid will be transmitted to the portion of the testing string 1 disposed at the wellhead and may be observable in the form of a flow or blow of fluid emanating from open passage means of the string 1 at the wellhead 21.

The fluid thus displaced in the passage 101 above the plug 6 may comprise gas such as air and/or may comprise liquid such as water or weighted fluid.

As will be appreciated, the nature of plug 6 is such that it cooperates with the cylindrical wall 102 of passage 101, between the stop means 301 and 701, to provide a translatable seal. This translatable or piston type seal prevents a transmission of fluid from the tester means 11 to the wellheads means 21 but does permit a flow of fluid into the perforate tail pipe portion 17 of the tester string and into and through the tester valve means 1 1.

Thus, solid plug means 6 is imperforate, i.e. nonvalved, and provides a translatable, but continuously effective, barrier or seal which permits flow tests in relation to a subterranean formation to be performed, and provides a surface indication of formation flow. This barrier prevents a transmission of formation fluid through the testing string to the wellhead and/or a flow of fluid past the barrier during sample recovery operations.

In this manner secrecy of a testing operation is preserved and a flow of dangerous or noxious well fluid to the surface is prevented.

With the structure and basic mode of operation of the barrier means having been'described, attention will now be directed to the indicator or signal means 8.

INDICATOR (SIGNAL) MEANS STRUCTURE Structural details of the indicator or signal means 8 are set forth in FIGS. through 8 as well as in FIGS. 50 through 8a.

FIGS. 5 through 8 illustrate components of the indicator means 8 as they are disposed, at the commencement of a testing operation, in a normal or neutral condition.

FIGS. 5a through 8a illustrate a disposition of indicator means components operable to provide an indication or signal at the wellhead, responding to a generation of pressure within the passage 101. Such a generation of pressure would result when the plug or barrier 6 was seated on the stop 301 and the pressure of formation fluid was being transmitted to the interior of passage 101, thereby causing a pressure buildup in response to formation pressure in this testing string passage zone.

Indicator or signal means 8, which functions to generate an impact or weight increase signal (detectable at the wellhead by observing the weight" of the testing string 1 effectively supported by support means 22), comprises generally telescopingly assembled first and second body portions 801 and 802.

Body portion 801 may comprise threadably interconnected, generally cylindrical components 803 and 804. A second body means 802 may comprise threadably interconnected components of a generally cylindrical nature including components 805, 806, 807 and 808.

A detent means 809, generally depicted in FIGS. 5 and 8, is operable to secure the first and second body portions 801 in a first, predetermined, telescopingly extended position generally depicted in FIGS. 5 through 7.

Detent means 809 may comprise a series of circumferentially spaced, detent segments 810 carried-in radially extending aperture portions 811 of body portion 805. Detent means segments 810, when biased or disposed in a radially outward position as shown in FIG. 5, extend or project into an annular and inwardly facing recess 812 carried by body portion 804'. This disposition of the detent segments 810 in recess 812 effectively interlocks body portions 801 and 802 in a first, telescopingly extended position and thereby substantially prevents telescoping or relative lineal movement of these conduit body portions.

Detents 810 are secured in the FIG. 5 position by a pressure responsive sleeve means 813.

As shown in FIGS. 5 and 6, pressure responsive sleeve means includes an outwardly facing, cylindrical surface 814 which is operable to engage the inner surfaces of segments 810, and thus secure these segments in locking cooperation with recess 812.

Pressure responsive sleeve means 813 includes an outwardly extending, annular piston means 815. As shown in FIG. 6, piston 815 is telescopingly mounted in an annular recess 816 of body portion 806. To facilitate upward movement of sleeve 813, recess 816, above piston 815 disposed in its FIG. 6 position, may be evacuated. In any event, area 816 above piston 815 will be either occupied by a vacuum or by a readily compressible medium or be vented.

Fluid acting on the underside of piston 817 of piston 815 will be operable to cause the sleeve 813 to move upwardly. Such upward movement of sleeve 813 will serve to bring an outwardly facing, annular recess 818 into radial alignment with the segment 810. When this occurs, the segments 810 will be operable, because of their generally radially sliding mounting in apertures 81 1, tomove radially inwardly, out of locking cooperation with recess 812.

Thus, upward movement of sleeve 813, in response to pressure acting on piston 815, will effect the releasing of the detent means 809 so as to permit relative converging or telescoping movement of conduit portions 801 and 802.

As will be appreciated, this telescoping movement will be relatively abrupt so as to provide an abrupt increase in the apparent weight of the testing string 1 supported by the means 22. It is contemplated that this converging movement may be such as to permit mutually facing, annular abutment means 819 and 820, carried respectively by the first and second conduit portions 801 and 802, to be brought into abrupt impacting cooperation so as to provide an impact signal readily detectable at the wellhead, reflecting converging or telescoping movements of the body portions 801 and 802.

The aforesaid upward movement of sleeve 813 may be effected by transmitting fluid from well bore 19, externally of testing string 1, through passage means in body portion 802 to the underside-of piston 815, i.e. to surface 817.

Such passage means may comprise longitudinally extending passage means 821 formed in body portion 807 and communicating directly with the underside surface 817 of pisotn 815. As shown in FIG. 7, passage means 821, at its lower end, communicates with radially extending or transversely extending passage means 822 also carried by body component 807. Passage means 822 extends radially inwardly and terminates on an inner face 823 of component 807.

Another radially or transversely extending passage means 824, carried by component 807, provides communication with the exterior of well bore 19, surrounding testing string 1. When passage means 824 is placed in fluid communication with passage 821, well fluid will flow from the exterior of the testing string 1, through passage 824, upwardly into passage means 822, and from passage means 822 through passage mmeans 821 to piston 815; i.e., to surface 817.

The pressure of fluid in the well annulus 190 may be selectively controlled from the well head, if necessary, to insure that the pressure-of fluid thus transmitted to piston 815 will be sufficient to induce upward movement of the sleeve 813 and permit the aforesaid releasing action of the detent means 809. Ordinarily annulus pressurizing is not necessary.

In effecting sleeve movement in this manner, an operator places reliance upon the controllable pressure of fluid in the well annulus and does not depend upon the uncertain pressure conditions of formation fluid which may occupy the interior passage 101.

Control over the passage of annulus fluid between passage means 824 and 822 is effected by a differential pressure operated sleeve means 825.

As shown in FIG. 7, sleeve means 825 is carried by body portion 802 and is disposed in telescoping cooperation with component 807 Sleeve 825 includes a longitudinally and circumferentially extending and radially outwardly facing recess 826. When sleeve 825 is disposed in its lower position, as shown in FIG. 7, recess 826 is displaced from passage 822. However, when sleeve 825 is elevated, the recess 826 is brought into communication with each of the passage means 822 and 824 so as to permit a transfer of annulus fluid from the zone 19a external of the testing string, consecutively through passage means 824, recess 826, passage means 822, and the passage 821 for transmittal to piston 815.

Transmission of annulus fluid into the interior passage 101 may be prevented by conventional O-type, seal ring means 827.

Differential pressure operated sleeve 825 is biased to the lower or neutral position shown in FIG. 7 by a conventional, compression type, coil spring 828. Coil spring 828 encircles the outer periphery of the lower portion of sleeve 825 and engages, at its lower end, an upwardly facing shoulder 829 carried on the outer periphery of sleeve 825. The upper end of spring 828 engages, and is thus secured by, a generally radially extending and downwardly facing edge or shoulder 830 of body component 807.

Lower portion 831 of sleeve 825 has an outer surface 832 having a diameter which somewhat exceeds the diameter of external wall portion 833 of upper sleeve portion 824. This difference in diameters of upper and lower sleeve portions, coupled with the constant diameter internal surface 835 of sleeve 825, provides a differential piston which yields a differential area or pressure effect. With this differential pressure effect, a pressure of fluid within passage 101 in the vicinity of sleeve 825 will provide a differential pressure acting upwardly on sleeve 825. When this pressure differential acting upwardly is sufficient to overcome the downward bias force of spring 828, the sleeve 825 will shift upwardly so as to bring the passage portions 824 and 822 into mutually communicating relation via recess 826.

Thus, during a flow phase of a well testing operation, when the barrier or plug 6 has engaged the stop 301, a pressure buildup will occur in passage 101 beneath plug 6 and adjacent sleeve 825, resulting from formation pressure being transmitted to fluid in the passage 101. When this pressure buildup reaches a predetermined level, as determined by the differential pressure necessary to overcome the biasing influence of Spring 828, sleeve 825 will shift upwardly and allow the pressure of annulus fluid external of passage 824 to be transmitted to piston 815. This transmission of pressure will cause sleeve 813 to shift upwardly and free the detent segments 810. This sleeve shift, in turn, will permit relative converging movement of body portions of 801 and 802 and generate a surface detectable signal.

The disposition of the components of signal or indicating means 8, after the aforesaid telescoping movement of conduitbody portions 801 and 802 has occurred, is illustrated in FIGS. 5a through 8a.

Thus, FIG. 7a illustrates the differential pressure operated sleeve 825 disposed in an elevated position such that fluid pressure from the well bore annulus is transmitted through passage means 824, recess 826 and passage means 822 and 821 to piston 15.

As shown in FIG. 6a this transmission of pressure to piston 815 has caused the piston and its sleeve 813 to elevate so as to permit the detent segments 810 to collapse radially inwardly into the sleeve recess 818. This collapse or radial inward movement of segments 810 out of recess 812 permits the body portion 801 to move downwardly relative to body portion 802, as generally depicted in FIG. 60.

As shown in FIG. 6a this relative convergence may be sufficient to bring the body portion surfaces 819 and 820 into abutting impact so as to insure the generation of a readily detectable, abrupt signal at the wellhead.

Even without the presence of the abutment means 819 and 820, the relative converging movements of body portions 801 and 802 would provide a change in indication of apparent weight of the testing string so that an operator could readily determine that abrupt to telescoping movement of the components 801 and 802 had occurred. This abrupt movement indicates, in a prompt mariner, that level has been obtained within the interior of passage 101 beneath the plug means 6.

The relative converging movements of the component 801 and 802, heretofore discussed is facilitated by providing venting means in the telescoping joint area between these body portions.

Thus, as shown in FIG. 5, body component 804 may be provided with a vent passage 835 which communicates with an upper zone 836 between components 804 and 805 to the exterior of the testing string. Another passage 837, carried by body component 805, communicates a lower zone 838 between components 804 and 805 with the interior passage 101.

The arrangement of passage 835 and area 836 permits annulus fluid to act downwardly on a piston on shoulder 839 carried by lower body portion 802 and thus offset any buoyant" force acting on this body portion due to the head of annulus fluid acting on the closed, lower end of the testing string. This pressure equalizing effect minimizes the imposition of vertical forces on detents 810 caused by converging movement of elements 804 and 805 of body means 801 and 802, which forces might otherwise impede retracting movement of these detents.

This buoyant force may be offset, for example, by the presence of a water cushion in passage 101. Passage 837 and cavity 838 enables this offsetting force, acting downwardly on body means 802 and tending to separate body means 801 and 802, to itself be substantially compensated. The pressure of fluid in passage 101, in being transmitted via passage 837 and cavity 838, would exert a lifting force on the underside of piston 839, tending to offset the aforesaid downwardly di rected force.

As will be understood, this downwardly directed force, by itself and to the extent not offset, would cause body element 805 to act downwardly on detents 810 and impede their movement.

In the manner heretofore described, both downwardly and upwardly directed hydraulic forces acting on body means 802, and tending to separate or converge body means 802 and 801 so as to impede movement of detent means 810, are at least in part offset or compensated so as to facilitate smooth retracting operations of detent means 810. in this manner, abrupt, timely operation of signal means isfacilitated.

It will be noted that axial separation of components 801 and 802 is prevented, even in the absence of the action of detent means 810, by the radially extending and outwardly projecting shoulder means 839. This shoulder means is carried by body component 805 between shoulder means 840 and 841 of body portion 801.

Relative rotation between body portions 801 and 802 is prevented by'spline means 842, depicted for example in FIG. 5.

In connection with the venting action inherently provided by passage means 837 and 835, it will be noted that this venting is accomplished without inducing any substantial impedance to telescoping movements, thereby avoiding the restrictive passage arrangement illustrated in the aforesaid Nutter US. Pat. No. 3,422,896. The Nutter arrangement, as disclosed, would inherently produce a substantial throttling or dash-pot action.

In summary, the present invention contemplates an invention such that, with the detent segments 810 released from the recess 812, abrupt converging movement of the body portions 801 and 802 may occur as topromptly generate a signal indicative of the generation of a particular pressure within tool body portion 101. The attainment of this pressure level, as indicated at the wellhead, will advise an operator at the wellhead that the fluid recovery operation has attained a prescribed pressure buildup level within the recovery chamber (i.e., the chamber above component and beneath the barrier 6 when barrier 6 is disposed in its upper position in engagement with stop 301.

Having described the manner in which the barrier means, including plug 6, functions to 1) permit a flow of formation fluid into the testing string, 2) prevent a transmission of this flow to the wellhead, and 3) indicate the beginning and termination of the flow in response to the beginning and termination of a wellhead blow correlated with movement of the plug 6, and

having described the manner in which the attainment of predetermined pressure buildup within the sample retaining cavity of the testing string is effected to respond to operation of indicator or signal means 8, it becomes appropriate to now consider the operation of the circulating valve means including the upper circulating valve 4 and the lower circulating valve 9. These circulating valves provide a cooperation arrangement permitting controlled removal of the sample of formation fluid from the tool cavity beneath the barrier means 6.

As will, be understood, the circulating valve means 4 and 9 will be operated only after an operator has closed tester and/or sampler valve means 1 l in response to detection of the signal indication provided by indicator or signal means 8. ln promptly responding to this signal or indication, an operator can close valve means 11 so as to isolate a formation fluid sample (below valve means 11 or in a chamber thereof) under optimum and/or desired gas/oil ratio conditions, etc.

v CIRCULATING VALVE MEANS STRUCTURE The circulating valve arrangement of the present invention is such that valve means 4 and 9, when open, enabled a displacing fluid to be passed into the passage 101 beneath the plug 6 and displace formation fluid which has passed into this area of the testing string during a flow phase of the testing operation.

The upper or first circulating valve means is manually operable and includes components shown in FIGS. 2, 2a, 3 and 4. a

As there shown, circulating valve 4 includes a valve opening or port means 401 formed in a cylindrical wall 402 of the testing string. A valve sleeve 403 is telescopingly mounted over opening 401 and includes a sample removal fitment 404.

Removal fitment 404 may comprise a threaded socket 405 operable to receive either a plug 406 or conduit means connection 407 (generally depicted in FIG. 2a).

Plug 406 may be apertured so as to provide fluid passage means, as shown in F IG. 3 or may comprise an imperforate sealing plug.

With sleeve 403 disposed as shown in FIG. 3, valve opening 401 is closed. This closing action is facilitated by various conventional O-type, seal rings 408.

Sleeve 403 is connected or telescopingly mounted on body means 402 by way of spline connection means 409. As shown in FIGS. 3 and 4, spline connection means may comprise a plug 410 threadably secured to the valve body'402 and projecting into a longitudinal slot 411. Slot 411 is formed on the interior of a lower portion of sleeve 403.

Longitudinal valving movement of sleeve 403 is manually effected by turnbuckle means 412.

Turnbuckle means 412 comprises a threaded sleeve 413 which is threadably engaged with a threaded lower portion 414 of valve sleeve 403. The lower end 415 of turnbuckle sleeve 413 is journaled on body portion 402 and is rotatably secured between flange 416 and a radial shoulder 417. Shoulder 417 may be provided by the upper end of a conduit section of conduit string 1 which is connected to the lower end of conduit or string portion 402.

With this arrangement, manually induced rotation of the turnbuckle sleeve 413 will cause or induce longitudinal valve movement of sleeve 403.

When this valving movement is such as to cause the sleeve 403 to move downwardly, the sleeve aperture or recess 405 will be brought into alignment with the opening 401.

If a fitting or connection 407 is connected with the socket 405, when the components are disposed in the FIG. 3 relationship, i.e. the closed valve relationship, downward movement of the sleeve 403 will bring the passage 401 into alignment with the fitting 407 so as to enable fluid from the formation sample cavity 101 to flow out of or into this cavity 101 via the alignment of openings 401 and the fitting 407.

The second or lower circulating valve means 9 is generally illustrated inFlGS. 9 through 11.

As shown in these figures, circulating valve means 9 may be supported on body component 808 of indicating means 8.

Circulating valve means may comprise a generally cylindrical body portion 901.

Body portion 901 may itself support rupturable passage means 902 and pressure relief valve means 903.

The rupturable means 902, as shown in FIGS. 9 and 11, may comprise a threaded fitting 904, threaded into body portion 901. A rupturable disc or disphragm 905 is secured against a shoulder portion 906 of fitting 904 by a threaded ring 907.

With this arrangement, the attainment of a particular pressure level in passage portion 101 adjacent diaphragm or disc 905 will effect the rupturing of this disc so as to permit a flow of fluid through a central passage 908 of fitting 904. With the disc 905 ruptured, fluid communication is thus provided between the interior and exterior of the conduit means portion 901 of the overall testing string.

The pressure relief valve means 903, as shown in FIG. 9 and in greater enlarged detail in FIGS. 10 and 10a, includes a plug-like fitting 909 threadably secured within body 901.

Fitment 909 includes a restricted passage or orifice 910 which is operable to provide fluid communication between cavity or passage 101 and the exterior of the testing string.

A valve 911 is mounted in an interior passage 912 of fitment 909 and is operable to engage a generally frustoconical valve seat 913. Valve 911 is biased against valve seat 913 by a conventional, compression spring 914.

The inner end of compression spring 914 engages valve body 911 while the outer end is anchored by or secured to a bracket means 915. Bracket means 915, as shown in expanded view in FIG. 10a and in assembled view in FIG. 10, comprises an anchor ring 916 including circumferentially spaced flow passage means 917. A snap ring 918 serves to secure flange 916 in the FIG. 10 disposition and prevent its outward movement.

Pressure relief valve means 903 is operable, during the time a testing string is being raised at the conclusion of a testing operation, to vent the portion of passage 101 containing a sample of formation fluid when [in the event] the pressure in the interior of the tool exceeds the pressure in the exterior. The venting pressure differential will be determined by the strength of spring 914.

Thus, during static conditions when the string is being raised with the space 101 occupied by formation fluid, the increase in pressure differential will serve to automatically open vent valve 903 when the pressure differential exceeds a limit deemed acceptable for safety purposes. Were this arrangement not provided, the pressure differential might be such as to induce premature rupturing of the disc 905. Such premature rupturing could cause the entire formation sample to be lost during the raising of the testing string, and thus defeat the overall ample recovery operation.

As will be appreciated, the restrictive nature of orifice 910 is such that, under flow conditions, where fluid is flowing from the interior space 101 outwardly through the open valve 903, a pressure buildup may be achieved within the cavity 101 adjacent disc 905 sufficient to induce rupturing of this disc.

Thus, by pressurizing the interior space 101 adjacent disc 905 to an extent such that valve 903, when open, does not possess sufficient flow capacity to adequately relieve the pressure buildup, rupturing of the disc 905 may be effected.

With the overall components of the apparatus having been described, it'now becomes appropriate to consider the manner in which a testing operation may be performed, particularly with reference to operation of the components 3, 4, 5, 6, 7, 8 and 9.

The operation of these components will now be described with reference to FIGS. la through If.

MODE OF OPERATION As shown in FIG. 1, testing is initiated by disposing the testing string 1 in the well bore 19.

Through operation of tester string components and manipulationof the tester string, in manners now well understood, the packer 16 may be expanded so as to isolate the formation 20 from the annulus zone 19a above the set packer 16. In this manner, the interior 101 of the testing string beneath the barrier plug 6 is placed in fluid communicating relation with the fluid of formation means 20.

When the testing operation is initiated, the plug 6 will be disposed in its lower position, supported on stop means 7.

Once testing commences, as generally shown in FIG. lb, the flow of fluid into the interior 101 of the testing string, as permitted by the opening of valve means 11, will induce upward movement of the plug 6. This upward movement of the plug 6 continues until plug 6 comes to rest against the upper stop means 3.

The initiation of this movement of the plug 6 will initiate a blow or flow of fluid at the well head, out of passage means in the upper end of the testing string 1. This initiation of flow at the well head or bow will advise the operator of the initiation of flow of formation fluid into the passage portion 101 beneath the barrier or plug 6.

When plug 6 comes to rest against the stop means 3, this blow or flow at the well head will cease and an operator will thus be advised of the seating of the plug 6 and termination of flow.

With plug 6 seated, pressure will rise in cavity 101 beneath the seated plug 6 until the detent means 809 of indicator means 8 is released. This releasing action willpermit the convergence of body portions 801 and 802 generally depicted in FIG. 1c. This convergence or collapsing of the telescoping means 801 and 802, resulting from downward movement of body means 801, will provide a well head indication that a pressure level has been obtained in cavity 101 sufficient to induce the tripping action of indicator means 8. This tripping action will be abrupt and prompt so that an operator will be promptly advised that a predetermined pressure level has been achieved.

In being thus promptly informed of the predetermined pressure level, the testing string can be promptly manipulated so as to close the valve 11 and prevent the generation of an excessive pressure in the cavity 101 in the sample entrapping chamber portion of passage 101, extending above valve 11 and beneath the set plug. This insures a more representative gas-oil ratio in the sampler (comprising valve 11 and/or sample chamber) then would otherwise be obtained if too little or too much time had elapsed.

With the operator being advised of the attainment of a desired pressure buildup in tool cavity 101, and with the testing operation having been concluded by the closing of valve means 11, an operator may then manipulate support means 22 so as to effect the raising of the testing string to the position generally shown in FIG. 1d.

As shown in FIG. 1d, the testing string has been raised so as to bring valve means 4 to the vicinity of well head 21.

As generally shown in FIG. 1d, a conduit fitting 407 has been connected with sleeve 403 of valve means 4 and turn buckle 413 has been operated so as to place the interior 101 of the testing string (beneath plug 6) in fluid communication with the interior of the conduit extending away from fitting 407.

In this connection it will be appreciated, by reference to FIG. 1, that plug 6, when engaged with seat 301, serves to position valve passage or opening 401 and fitting 407 beneath this plug.

As schematically depicted in FIG. 1e, pressurized fluid may be transmitted from pump means to fitment 407 so as to intensely pressurize the interior 101 of the testing string and induce the rupturing of disc 905 in the manner heretofore indicated.

With disc 405 thus ruptured, conventional annulus pressurizing pump means may be operated so as to reverse circulate annulus fluid into passage 908. This will displace the recovered sample from cavity 101, out of passage 401 and into a conduit means extending from valve means 4 for sample recovery purposes.

Conventional valve mechanisms associated with the conduit extending from valve means 4 and associated with the pump system for pressurizing the annulus may be employed to rapidly switch flow conditions from the pressurizing and disc rupturing arrangement shown in FIG. 1e to the sample recovery arrangement shown in FIG. 1f where fluid is flowing from valve means 4 to a sample recovery zone 23.

As will be apparent, other circulation techniques might be employed under certain circumstances to effect the removal of sample fluid from the cavity 101. It is conceivable, for example, that the disc 905 might be ruptured by internal pressure so as to permit the sample fluid to be displaced into the annulus in response to downward movement or by passing of plug 6 before starting out of the hole.

SUMMARY OF MAJOR ADVANTAGES AND SCOPE OF INVENTION A particularly significant advantage of the invention is attributable to the manner in which the barrier mechanism positively and continuously insures that formation fluid will not be transmitted to a well head during a sample gathering and pressuring testing operation and will not flow past the barrier mechanism during sample removal.

Significantly, this control and/or safety aspect is achieved without impairing the efficiency of a testing operation.

Furthermore, the possibility of human or mechanical error permitting an inadvertent flow of fluid to the well head or past the barrier mechanism is avoided.

The manner in which the indicating or signaling mechanism provides a prompt indication at the well head of the generation of a particular pressure level in the sample recovery zone of the testing string provides prompt and timely information to an operator. This prompt and timely information enables an operator to terminate a testing operation at the optimum time to obtain a representative sample and without producing an excessive buildup within the interior of a testing string.

The overall circulating valve system provides an improved and simplified arrangement for removing a sample from a testing string, in conjunction with maximum secrecy operation or conditions.

These advantages, either individually or in a combination sense, afford a significant improvement in relation to controlled formation evaluation operations.

Those skilled in the testing art and familiar with this disclosure may recognize additions, deletions, substitutions or other modifications which would fall within the purview of the invention as set forth in the appended claims.

What is claimed is:

1. An apparatus for testing the productivity of well formations comprising:

weli formation testing means;

conduit means operable to extend from said well formation testing means to wellhead means; barrier means translatable within said conduit means and operable to permit a flow of formation fluid through said well formation testing means but block a transmittal of fluid from said well formation testing means to said wellhead means, said barrier means including, first stop means carried by said conduit means, second stop means carried by said conduit means,

and barrier means carried by said conduit means between said first and second stop means, said barrier means being operable to translate between said first and second stop means in response to a flow of fluid from said well formation testing means through said conduit means, while preventing a passage of fluid from said well formation testing means to said wellhead means; abruptly operable means carried by said conduit I means and abruptly operable to indicate a generation of pressure within said conduit means in response to flow of well fluid through said well formation testing means; and

selectively operable circulating valve means operable to control the removal of fluid from said conduit means, beneath said barrier means, said circulating valve means being carried by said conduit means and at least comprising,

valve means carried by said conduit means beneath said first stop means operable to control fluid communication between the interior and exterior of said conduit means, and I means for effecting valving operation of said valve means for controlling the removal of fluid from said conduit means. 2. An apparatus for testing the productivity of well formations comprising:

well formation testing means; conduit means operable to extend from said well formation testing means to wellhead means; barrier means translatable within said conduit means and operable to permit a flow of formation fluid through said well formation testing means but block a transmittal of fluid from said well formation testing means to said wellhead means; abruptly operable means carried by said conduit means and abruptly operable to indicate a generation of pressure within said conduit means in response to a flow of well fluid through said well formation testing means said abruptly operable means including, generally telescoping assembled first and second portions of said conduit means, detent means operable to secure said first and second portions of said conduit means in a first predetermined portion, pressure responsive means movable, in response to exposure to fluid pressure external of said conduit means in said well bore, to release said detent means and permit relative movement of said first and second portions of said conduit means to a second position, and differential pressure operated means carried within said conduit means and operable in response to a generation of pressure therewithin to cause said pressure responsive means to be exposed to the pressure of fluid external of said conduit means; and selectively operable circulating valve means operable to control the removal of fluid from said conduit means, beneath said barrier means. 3. An apparatus for testing the productivity of well formations comprising:

well formation testing means; conduit means operable to extend from said well formation testing means to wellhead means; barrier means translatable within said conduit means and operable to permit a flow of formation fluid through said well formation testing means but block a transmittal of fluid from said well formation testing means to said well-head means; abruptly operable means carried by said conduit means and abruptly operable to indicate a generation of pressure within said conduit means in response to a flow of well fluid through said well formation testing means; and selectively operable circulating valve means operable to control the removal of fluid from said conduit means, beneath said barrier means, said circulating valve means including, first circulating valve means carried by said conduit means and including sleeve valve means carried by said conduit means operable to control fluid communication between the interior and exterior of said conduit means,

turnbuckle means, manually operable at said wellhead means, to effect valving operation of said sleeve valve means, and second circulating valve means carried by said conduit means and including rupturable means carried by said conduit means and operable when ruptured, to provide fluid communication between the interior and exterior of said conduit means, and

pressure relief valve means operable to limit the generation of static pressure within the interior of said conduit means adjacent said rupturable means; i

said first and second circulating valve means being spaced longitudinally of said conduit means. 4. An apparatus for testing well formations, said apparatus comprising:

well formation testing means; conduit means operable to extend from said well formation testing means, disposed in a well bore, to wellhead means, and including upper stop means carried by said conduit means, lower stop means carried by said conduit means,

and barrier means carried by said conduit means between said upper and lower stop means, said barrier means being operable to translate b'etweensaid lower and upper stop means in response to a flow of fluid from said well formation testing means through said conduit means, while preventing a passage of fluid from said well formation testing means to said wellhead means; said barrier means being operable to provide an indication of a flow of well fluid into said well formation testing means; selectively operable circulating valve means operable to control the removal of fluid from said conduit means, including at least valve means carried by said conduit means and positioned beneath said upper stop means to control fluid communication between the interior and exterior of said conduit means; said barrier means being further operable to provide a continuously effective barrier between said upper stop means and the interior of said conduit means above said barrier means while fluid is being removed from the interior of said conduit means through said valve means beneath said upper barrier means. 5. An apparatus for testing well formations, said apparatus comprising:

well formation testing means; conduit means operable to extend from said well formation testing means, disposed in a well bore, to wellhead means, and including first stop means carried by said conduit means, second stop means carried by said conduit means,

and barrier means carried by said conduit means between said first and second stop means, said barrier means being operable to translate between said first and second stop means in response to a flow of fluid from said well formation testing means through said conduit means, while preventing a passage of fluid from said well formation testing means to said wellhead means;

said barrier means bbeing being to provide an indication of a flow of well fluid into said well formation testing means; said barrier means being further operable to provide a continuously effective barrier between said first and second stop means and the interior of said conduit means above said barrier means while fluid is being removed from the interior of said conduit means beneath said barrier means; and abruptly operable impact means operable to indicate the generation of pressure within said conduit means, said abruptly operable impact means including generally telescoping assembled first and second portions of said conduit means, detent means operable to secure said first and second portions of said conduit means in a first predetermined position, pressure responsive sleeve means movable, in response to exposure to fluid pressure external of said conduit means in said well bore, to release said detent means and permit relative movement of said first and second portions of said conduit means to a second position, and differential pressure operated means carried within said conduit means and operable in response to a generation of pressure therewithin to cause said pressure response sleeve means to be exposed to the pressure of fluid external of said conduit means. 6. Apparatus for testing well formations, said apparatus comprising:

well formation testing means: conduit means operable to extend from said well formation testing means, disposed in a well bore, to ellhead means, and including first stop means carried by said conduit means, second stop means carried by said conduit means,

and barrier means carried by said conduit means between said first and second stop means, said barrier means being operable to translate between said first and second stop means in response to a flow of fluid from said well formation testing means through said conduit means, while preventing a passage of fluid from said well formation testing means to said wellhead means; said barrier means being operable to provide an indication of a flow of well fluid into said well formation testing means; said barrier means being further operable to provide a continuously effective barrier between said first and second stop means and the interior of said conduit means above said barrier means while fluid is being removed from the interior of said conduit means beneath said barrier means; first circulating valve means carried by said conduit means and including sleeve valve means carried by said conduit means operable to control fluid communication between the interior and exterior of said conduit means, turnbuckle means, manually operable at said wellhead, to effect valving operation of said sleeve valve means; and second circulating valve means carried by said conduit means and including rupturable means carried by said conduit means and operable when ruptured, to provide fluid communication between the interior and exterior of said conduit means, and pressure relief valve means operable to limit the generation of static pressure within the interior of said conduit means adjacent said rupturable means; said first and second circulating valve means being spaced longitudinally of said conduit means. 7. An apparatus for testing well formations, said apparatus comprising;

well formation testing means; conduit means operable to extend from said well formation testing means, disposed in a well bore, to wellhead means; and including first stop means carried by said conduit means, second stop means carried by said conduit means,

and barrier means carried by said conduit means between said first and second stop means, said barrier means being operable to translate between said first and second stop means in re sponse to a flow of fluid from said well formation testing means through said conduit means, while preventing a passage of fluid from said well formation testing means to said wellhead means; said barrier means being operable to provide an indication of a flow of well fluid into said well formation testing means; abruptly operable impact means operable to indicate the generation of pressure within said conduit means, said abruptly operable impact means including generally telescopingly assembled first and second portions of said conduit means, detent means operable to secure said first and second portions of said conduit means in a first predetermined decision, pressure responsive sleeve means movable, in response to exposure to fluid pressure external of said conduit means in said well bore, to release said detent means and permit relative movement of said first and second portions of said conduit means to a second position, and differential pressure operated means carried within said conduit means and operable in response to a generation of pressure therewithin to cause said pressure responsive sleeve means to be exposed to the pressure of fluid external of said conduit means; first circulating valve means carried by said conduit means and including sleeve valve means carried by said conduit means operable to control fluid communication between the interior and exterior of said conduit means, turnbuckle means, manually operable at said wellhead, to effect valving operation of said sleeve valve means; and second circulating valve means carried by said conduit means and including rupturable means carried by said conduit means and operable when ruptured, to provide fluid communication between the interior and exterior of said conduit means, and pressure relief valve mmeans operable to limit the generation of static pressure within the interior of said conduit means adjacent said rupturable means; said first and second circulating valve means being spaced longitudinally of said conduit means.

* i 1K i TED STATES PATENT OFFICE GE'IIFICATE OF GORRECTION Patent No. 3,762,219 Dated October 2, 1973 Inventor) Robert L. Jessy It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In column 1 at line 52, change Nucler'" to --Nutter-.

In column 6 at line 24, change "not" to --noW--.

In column 9 at line 15, change "mmeans" to -means.

In column 10 at line 48, change "co" to or- In column 12 at line 9, change "cooperation to cooperable-.

In column 14 at line 7, change ample'zto sample- In column 14 at line 51, change "bow" to --blow-.

In claim 2, columnl7 at line 26, change "portion to -position.

In claim 7, column 20 at line 36, change "decision" to posicion--.

In claim 7, column 20 at line 62, change "mmeans' to --means.

Signed and sealed this 19th day of February 19714..

(SEAL) Attest: Y W, MW WM m EDWARD M.FLETCHER, JR. MARSHALL DANN Attesting Officer Commissioner f Pat nts FORM PO'WSO (10-69) I uscoMM-oc 60376-P69 fi U. 5. GOVERNMENT PRINTING OFFICE I 19.9 0-556-33, 

1. An apparatus for testing the productivity of well formations comprising: well formation testing means; conduit means operable to extend from said well formation testing means to wellhead means; barrier means translatable within said conduit means and operable to permit a flow of formation fluid through said well formation testing means but block a transmittal of fluid from said well formation testing means to said wellhead means, said barrier means including, first stop means carried by said conduit means, second stop means carried by said conduit means, and barrier means carried by said conduit means between said first and second stop means, said barrier means being operable to translate between said first and second stop means in response to a flow of fluid from said well formation testing means through said conduit means, while preventing a passage of fluid from said well formation testing means to said wellhead means; abruptly operable means carried by said conduit means and abruptly operable to indicate a generation of pressure within said conduit means in response to flow of well fluid through said well formation testing means; and selectively operable circulating valve means operable to control the removal of fluid from said conduit means, beneath said barrier means, said circulating valve means being carried by said conduit means and at least comprising, valve means carried by said conduit means beneath said first stop means operable to control fluid communication between the interior and exterior of said conduit means, and means for effecting valving operation of said valve means for controlling the removal of fluid from said conduit means.
 2. An apparatus for testing the productivity of well formations comprising: well formation testing means; conduit means operable to extend from said well formation testing means to wellhead means; barrier means translatable within said conduit means and operable to permit a flow of formation fluid through said well formation testing means but block a transmittal of fluid from said well formation testing means to said wellhead means; abruptly operable means carried by said conduit means and abruptly operable to indicate a generation of pressure within said conduit means in response to a flow of well fluid through said well formation testing means said abruptly operable means including, generally telescoping assembled first and second portions of said conduit means, detent means operable to secure said first and second portions of said conduit means in a first predetermined portion, pressure responsive means movable, in response to exposure to fluid pressure external of said conduit means in said well bore, to release said detent means and permit relative movement of said first and second portions of said conduit means to a second position, and differential pressure operated means carried within said conduit means and operable in response to a generation of pressure therewithin to cause said pressure responsive means to be exposed to the pressure of fluid external of said conduit means; and selectively operable circulating valve means operable to control the removal of fluid from said conduit means, beneath said barrier means.
 3. An apparatus for testing the productivity of well formations comprising: well formation testing means; conduit means operable to extend from said well formation testing means to wellhead means; barrier means translatable witHin said conduit means and operable to permit a flow of formation fluid through said well formation testing means but block a transmittal of fluid from said well formation testing means to said well-head means; abruptly operable means carried by said conduit means and abruptly operable to indicate a generation of pressure within said conduit means in response to a flow of well fluid through said well formation testing means; and selectively operable circulating valve means operable to control the removal of fluid from said conduit means, beneath said barrier means, said circulating valve means including, first circulating valve means carried by said conduit means and including sleeve valve means carried by said conduit means operable to control fluid communication between the interior and exterior of said conduit means, turnbuckle means, manually operable at said wellhead means, to effect valving operation of said sleeve valve means, and second circulating valve means carried by said conduit means and including rupturable means carried by said conduit means and operable when ruptured, to provide fluid communication between the interior and exterior of said conduit means, and pressure relief valve means operable to limit the generation of static pressure within the interior of said conduit means adjacent said rupturable means; said first and second circulating valve means being spaced longitudinally of said conduit means.
 4. An apparatus for testing well formations, said apparatus comprising: well formation testing means; conduit means operable to extend from said well formation testing means, disposed in a well bore, to wellhead means, and including upper stop means carried by said conduit means, lower stop means carried by said conduit means, and barrier means carried by said conduit means between said upper and lower stop means, said barrier means being operable to translate between said lower and upper stop means in response to a flow of fluid from said well formation testing means through said conduit means, while preventing a passage of fluid from said well formation testing means to said wellhead means; said barrier means being operable to provide an indication of a flow of well fluid into said well formation testing means; selectively operable circulating valve means operable to control the removal of fluid from said conduit means, including at least valve means carried by said conduit means and positioned beneath said upper stop means to control fluid communication between the interior and exterior of said conduit means; said barrier means being further operable to provide a continuously effective barrier between said upper stop means and the interior of said conduit means above said barrier means while fluid is being removed from the interior of said conduit means through said valve means beneath said upper barrier means.
 5. An apparatus for testing well formations, said apparatus comprising: well formation testing means; conduit means operable to extend from said well formation testing means, disposed in a well bore, to wellhead means, and including first stop means carried by said conduit means, second stop means carried by said conduit means, and barrier means carried by said conduit means between said first and second stop means, said barrier means being operable to translate between said first and second stop means in response to a flow of fluid from said well formation testing means through said conduit means, while preventing a passage of fluid from said well formation testing means to said wellhead means; said barrier means bbeing being to provide an indication of a flow of well fluid into said well formation testing means; said barrier means being further operable to provide a continuously effective barrier between said first and second stop means and the interior of said conduit means above said barrier means wHile fluid is being removed from the interior of said conduit means beneath said barrier means; and abruptly operable impact means operable to indicate the generation of pressure within said conduit means, said abruptly operable impact means including generally telescoping assembled first and second portions of said conduit means, detent means operable to secure said first and second portions of said conduit means in a first predetermined position, pressure responsive sleeve means movable, in response to exposure to fluid pressure external of said conduit means in said well bore, to release said detent means and permit relative movement of said first and second portions of said conduit means to a second position, and differential pressure operated means carried within said conduit means and operable in response to a generation of pressure therewithin to cause said pressure response sleeve means to be exposed to the pressure of fluid external of said conduit means.
 6. Apparatus for testing well formations, said apparatus comprising: well formation testing means: conduit means operable to extend from said well formation testing means, disposed in a well bore, to ellhead means, and including first stop means carried by said conduit means, second stop means carried by said conduit means, and barrier means carried by said conduit means between said first and second stop means, said barrier means being operable to translate between said first and second stop means in response to a flow of fluid from said well formation testing means through said conduit means, while preventing a passage of fluid from said well formation testing means to said wellhead means; said barrier means being operable to provide an indication of a flow of well fluid into said well formation testing means; said barrier means being further operable to provide a continuously effective barrier between said first and second stop means and the interior of said conduit means above said barrier means while fluid is being removed from the interior of said conduit means beneath said barrier means; first circulating valve means carried by said conduit means and including sleeve valve means carried by said conduit means operable to control fluid communication between the interior and exterior of said conduit means, turnbuckle means, manually operable at said wellhead, to effect valving operation of said sleeve valve means; and second circulating valve means carried by said conduit means and including rupturable means carried by said conduit means and operable when ruptured, to provide fluid communication between the interior and exterior of said conduit means, and pressure relief valve means operable to limit the generation of static pressure within the interior of said conduit means adjacent said rupturable means; said first and second circulating valve means being spaced longitudinally of said conduit means.
 7. An apparatus for testing well formations, said apparatus comprising: well formation testing means; conduit means operable to extend from said well formation testing means, disposed in a well bore, to wellhead means; and including first stop means carried by said conduit means, second stop means carried by said conduit means, and barrier means carried by said conduit means between said first and second stop means, said barrier means being operable to translate between said first and second stop means in response to a flow of fluid from said well formation testing means through said conduit means, while preventing a passage of fluid from said well formation testing means to said wellhead means; said barrier means being operable to provide an indication of a flow of well fluid into said well formation testing means; abruptly operable impact means operable to indicate the generation of pressure within said conduit means, said abruptly operable impact means includinG generally telescopingly assembled first and second portions of said conduit means, detent means operable to secure said first and second portions of said conduit means in a first predetermined decision, pressure responsive sleeve means movable, in response to exposure to fluid pressure external of said conduit means in said well bore, to release said detent means and permit relative movement of said first and second portions of said conduit means to a second position, and differential pressure operated means carried within said conduit means and operable in response to a generation of pressure therewithin to cause said pressure responsive sleeve means to be exposed to the pressure of fluid external of said conduit means; first circulating valve means carried by said conduit means and including sleeve valve means carried by said conduit means operable to control fluid communication between the interior and exterior of said conduit means, turnbuckle means, manually operable at said wellhead, to effect valving operation of said sleeve valve means; and second circulating valve means carried by said conduit means and including rupturable means carried by said conduit means and operable when ruptured, to provide fluid communication between the interior and exterior of said conduit means, and pressure relief valve mmeans operable to limit the generation of static pressure within the interior of said conduit means adjacent said rupturable means; said first and second circulating valve means being spaced longitudinally of said conduit means. 